胃癌の切除範囲決定に関する問題点―切除する立場から

Some Considerations about the Determination of the Surgical Incision Line in Gastric Cancer Surgery

要旨　胃癌の切除範囲決定に際し，外科的立場から切除断端癌陽性および不必要な胃全摘の問題を取り上げた．対象は過去14年間に切除された胃癌955例のうち切除断端(OW)が問題となった38例(早期癌6例，進行癌32癌)である．OW(＋)の30例はすべて進行癌であり，そのうち28例までがOW以外の理由で絶対的非治癒となったものである．追加切除を余儀なくされた症例は8例であり，早期癌(6例)の場合は表層拡大型のⅡb，Ⅱcであり，切除線決定には労を惜しまず各種画像診断(ゾンデ法，色素内視鏡，段階的生検)を駆使し，かつ術中断端迅速標本に供すべきである．進行癌では浸潤性発育を示す硬癌が多く，超音波内視鏡も有用である．次に胃全摘を施行した早期癌35例について検討したところ，12例までが大きさ5cm以内で，リンパ節転移もなく，切除範囲を縮小しても十分根治性が期待された．

　This paper discusses some problems in determining more accurately the surgical incision line for gastric cancer infiltration, before or during surgery. It is desirable to avoid unnecessary total gastrectomy often done despite the limited extent of the disease. Out of 955 gastric cancer cases in which gastrectomy was performed at our institution there were 38 cases (6 early cancer, 32 advanced cancer cases) which might be questioned as to the choice of the best surgical incision line. However, 28 of 30 far-advanced cases with positive indications of cancer cells at the surgical cut end were excluded in this discussion because of the absolute impossibility of cure by resection, e.g., carcinomatous peritonitis, hepatic metastasis, massive nodal involvement and generalized metastases. We encountered 8 cases in which we were obliged to carry out additional resection of the remnant stomach due to positive indications of cancer cells in the surgical incision line discovered in the frozen surgical section. These included one case with latent linitis plastica carcinoma. Consequently, in case of superficial spreading carcinoma we should pay careful attention to the determination of the incision line. In order to examine the cancer infiltrating boundary, it is necessary to employ various imaging analysis such as clear double contrast picture, dye endoscopy before surgery and frozen section of incision line at surgery. On the other hand, advanced gastric cancer with questionable cancerous boundary showed histological characteristics of scirrhous stroma, and endoscopic ultrasonography is useful to give information concerning the extent of cancerous infiltration into the gastric wall. Nextly, unnecessary total gastrectomy was discussed for gastric carcinoma arising in the upper part of the stomach, especially early and small gastric carcinoma. Thirty five cases of early gastric cancer in which total gastrectomy was performed because of location at the upper part of the stomach were collected in this series. In 12 out of the 35 cases the diameter of the lesioned area was less than 5 cm in size without nodal involvement. It is concluded that early gastric cancer located at the upper part of the stomach and being less than 5 cm in diameter, can be expected to be cured absolutely by performing reductive surgery only.